Description of the family

Terrestrial, epilithic or (rarely) epiphytic ferns with a short life cycle or perennial. Rhizomes short or long, suberect, decumbent or creeping, often laterally branched; roots few or many, often fleshy. Stipe not articulated, often dark-coloured. Fronds tufted or widely spaced, mono- or dimorphic. Lamina pinnately compound, pedate, dichotomously forked or helicoid, often with a proliferating bud at the rhachis apex, herbaceous or coriaceous, glabrous or variously set with indumentum; ultimate segments often articulated; venation free (in sterile fronds) or forming a network, without included veinlets, ending in or near the margin, often in hydathodes. Indumentum composed of unicellular glands on the abaxial surface of the lamina, or needle-like hairs occuring on the axes and lamina and/or scales on the rhizome and stipe. Sori variously arranged, exindusiate or covered by a strongly modified marginal indusium. Sporangia often mixed with paraphyses (sterile hairs).